adjective

consisting of two equal, identical, or similar parts or things.

double doors

dual,duplex,twin,binary,duplicate,matched,matching,paired,in pairs,complementary,coupled,twofold,binate

predeterminer

twice as much or as many.

the jail now houses almost double the number of prisoners it was designed for

adverb

at or to twice the amount or extent.

you have to be careful, and this counts double for older people

twice,twice over,twice the amount,doubly

noun

a thing which is twice as large as usual or is made up of two standard units or things.

join the two sleeping bags together to make a double

pronoun

a number or amount which is twice as large as a contrasting or usual number or amount.

he paid double and had a room all to himself

verb

become twice as much or as many.

profits doubled in one year

multiply by two,increase twofold,enlarge,magnify,repeat